Such sensor chips are used in computerized tomography detectors (CT detectors) which are used for medical imaging. A computer tomograph permits better diagnosis if a high resolution, i.e. a high number of pixels per surface, is ensured. One sensor chip usually corresponds to one pixel, whereby to achieve the desired resolution as a rule a multiplicity of sensor chips is required. Lithographic integration in semiconductor substrates is already advantageous for cost reduction on account of this multiplicity of pixels required.
In addition, the sensor chips must be suitable for arranging in a defined two-dimensional manner with additional sensor chips in order to precisely define the pixel spacing. Each dimension requires the flat arrangement of two adjacent sensor chips. Consequently, it must be possible to arrange a total of four sensor chips laterally. Especially for this quadrilateral arrangement requirement, as is conventional for large-area CT detectors, sensors based on semiconductor substrates are also highly suitable.
For example, DE 10 2007 022 197 A1 discloses a detector element for an X-ray detector for use in an X-ray computer tomograph. This detector element has a number of components based on semiconductor substrates, namely a detection element, a module with electronic circuits and a contact element which is arranged between the two aforementioned and has two functions, namely on the one hand to ensure mechanical stabilization of the sensor element and on the other hand to adapt the geometric arrangement of the signal output contacts of the detection element to the geometric arrangement of the signal input contacts of the module by way of its conductor paths.
A detector module for a radiation detector is known from DE 10 2010 011 582 B4 which has the function of an optoelectrical converter layer with downstream rewiring on the associated substrate, whereby on account of the novel arrangement of the signal output contacts the cable-based connection of the external readout electronics is easier.
The production and material costs are very high with the current solutions, particularly as a so-called wafer-bonding method often has to be employed or the contact costs are simply very high.